The Power Regulation Board is a new PCB that is the central power hub for all components on the Polaris. The board selects either the batteries or a tethered power source to power the sub, and is capable of cutting power via an onboard microcontroller to various systems in Polaris. RoboSub Rules requires that the sub have a “kill switch”, with can be pulled by divers to cut power to Polaris. This is implemented by using a magnetic switch, which cuts power to the sub when the switch is pulled. The Power Regulation Board must also be able to handle enough current to power the eight motors. This board also acts as a monitor for the main housing of Polaris by monitoring the housings’ pressure, temperature and humidity. It comes with an onboard water sensor, and it has the capabilities to measure the external water pressure. It measures the current being drawn from both the batteries and by individual subsystems, and has the ability to connect and disconnect the batteries in parallel using control logic from the microcontroller. The board is fused to protect against short circuits in any of the subsystems.
The board has a USB connector that can be used for USART communications. The microcontroller also has the capabilities to be powered either through USB or by the batteries, which is useful for debugging purposes, when batteries aren’t available. The relays are used to switch between battery power and tether power, and will always chose tether power over battery power when the tether is available. This can be used to easily conserve battery life during testing.